Pantangi, Venkata Raghu Tej. “Difference Families, Skew Hadamard Matrices, and Critical Groups of Doubly Regular Tournaments”. The Electronic Journal of Combinatorics 26, no. 3 (September 27, 2019): P3.59. Accessed March 15, 2026. https://www.combinatorics.org/ojs/index.php/eljc/article/view/v26i3p59.